Thera Freeballs Hand. Small balls which, thanks to their resiliency, allow to perform specific exercises for hand rehabilitation. The Thera Freeballs Hand are ideal also to develop finger mobility and to strengthen finger muscles. The set, which is made up of 2 balls, is packed in a small transparent box. A booklet with some exemplifying exercises is included in the package. 1 Ø 55 mm Red- 1 Ø 40 mm Yellow.